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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Assessment of Arbuscular Mycorrhizal Fungi in a Green Roof System

John, Jesse 08 August 2013 (has links)
Green roof design has proceeded without integration of arbuscular mycorrhizal fungi (AMF). A literature survey was therefore conducted in order to determine which aspects of green roof functioning might be enhanced by AMF, and subsequently levels of AMF and endophyte colonization were determined for seven plant species used in green roofs. Plants were sampled from an experimental green roof and from the field. A commercial growing medium was also tested for AMF inoculum potential. Colonization was poor in both field and rooftop samples of the commercially popular succulent, Sedum acre, but significantly higher in Solidago bicolor, a proposed green roof species. The commercial growing medium was found to contain extremely low levels of viable AMF propagules. Although the apparent lack of mycorrhizal dependency of S. acre helps to explain its popularity as a green roof plant, its overuse precludes the important ecosystem services potentially provided by AMF symbioses.
112

Microclimates and human comfort : cooling urban setting through design and manipulation of microclimatic factors

Doty, Tamera J. January 1992 (has links)
The goal of this creative project was to develop a unit to be incorporated into an environmental education general studies course at Ball State University. The unit was developed as a hands-on experience activity manual.The goals of the unit were:1. to increase student awareness of the effect vegetation and water have on human comfort in the urban environment.2. to engage students in hands-on activities that relate methods for manipulating the microclimate of a space.3. to develop a pre-test/post-test containing questions which relate to the activity topics and which determine the topic knowledge of students.The manual contains an introduction, four section activities and activity subsectionexercises to combine all techniques learned in the four activity sections. Each of the four sections contain a list of objectives for the activity, explanatory text, an activity procedure, and discussion questions. Illustrations accompany the manual in order to augment the learning process for each activity. / Department of Landscape Architecture
113

Plant- and arthropod diversity of vegetable gardens along a socio-economic gradient within the Tlokwe Municipal Area / Nicola Botha

Botha, Nicola January 2012 (has links)
Globally urbanization has increased to such an extent that more than half of the human population currently resides in cities. In the years to come, urban expansion will especially take place in developing countries through efforts to improve economic growth and poverty alleviation. This may have a negative effect on native biodiversity within and surrounding urban environments. However, residential areas with a high proportion of gardens form a significantly large part of urban environments and these domestic gardens contribute to the maintenance and preservation of biodiversity in cities. Although the preservation of biodiversity in these gardens is important in the overall conservation of urban green spaces, little is known about how these gardens can possibly contribute to conservation purposes in urban areas. Bearing in mind that anthropogenic activities are possible drivers of urban biodiversity, it is vital to quantify socio-economic aspects within urban ecological research. In developing countries, such as South Africa, the inclusion of socio-economic aspects are especially important because there is a wider gap between poor and wealthy households. There are also a larger number of people that are dependent on their gardens for subsistence purposes, such as vegetable gardening. In the Municipal Area of Tlokwe, South Africa, there exists a definite socio-economic gradient from the poorer western to the more affluent eastern part of the city. Five socio-economic status (SES) classes, primarily based on % unemployment, were used in this study. The ultimate aim of this study was therefore to determine the plant- and arthropod diversity within urban domestic gardens along a socio-economic gradient. Vegetable gardens within domestic gardens were selected to quantify plant- and arthropod biodiversity. Biodiversity of adjacent lawns were also sampled for comparative purposes. The study also attempted to determine to what extent socio-economic aspects of city residents may be possible drivers of biodiversity within the gardens. Various other factors that might have an effect on the plant and/or arthropod diversity were included such as soil characteristics, specific management factors of the gardens and other land-uses surrounding domestic gardens. Arthropod diversity was surveyd by means of pitfall traps and suction sampling in eight 0.25 m2 squares along an 8 m transect in each representative garden. Arthropods were identified up to morphospecies level. Vegetation was surveyed along the same transect and total species composition was determined. Plants were identified up to species level. The plant and arthropod surveys were conducted in both the vegetable gardens and lawns of all SES classes. For the soil samples a 1:2.5 water analysis was conducted. A social survey was conducted in all representative gardens by means of a questionnaire and a SPOT 5 satellite imagery was used to determine the land-use types in the areas surrounding the participating gardens. All the above mentioned factors were compared between the different SES classes. Diversity indices for the arthropods, multivariate statistical analyses and ANOVA analyses were applied to test for meaningful variables between socio-economic status classes as well as vegetable gardens and lawns. From the results it was evident that the more affluent SES classes had significantly higher arthropod diversity values, whilst the lower income classes had higher plant diversity. The factor analysis between the plants and arthropods with the surrounding land-uses revealed two significant factors. Firstly, arthropod diversity was influenced by domestic gardens in the surrounding landscape and there was a positive correlation between these two variables. This indicates that a high percentage of surrounding domestic gardens were possible drivers of arthropod diversity. No correlations were evident between plant and arthropod diversity. Secondly, the other significant factor showed that one SES class had a significantly higher percentage of woodlands and grasslands as opposed to two of the other classes that had a significantly higher percentage of built structures within the surrounding area. Differences were also apparent between the SES classes concerning management regimes, financial stability and level of education. The two more affluent SES classes had obtained a higher level of education and income and had management practices that were uncommon in the three poorer SES classes. This study proposes that domestic gardens are a means to conserve biodiversity in cities. Vegetable gardens in domestic gardens will also be able to harbour a larger diversity of plants and arthropods than the lawns. The socio-economic status of residents also had a significant effect on biodiversity and therefore it should be included in studies on urban domestic gardens. This study also provides additional knowledge to the fundamentals of the field of urban ecology and the importance of using domestic gardens as an urban green space for conservation purposes. / Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013
114

Plant- and arthropod diversity of vegetable gardens along a socio-economic gradient within the Tlokwe Municipal Area / Nicola Botha

Botha, Nicola January 2012 (has links)
Globally urbanization has increased to such an extent that more than half of the human population currently resides in cities. In the years to come, urban expansion will especially take place in developing countries through efforts to improve economic growth and poverty alleviation. This may have a negative effect on native biodiversity within and surrounding urban environments. However, residential areas with a high proportion of gardens form a significantly large part of urban environments and these domestic gardens contribute to the maintenance and preservation of biodiversity in cities. Although the preservation of biodiversity in these gardens is important in the overall conservation of urban green spaces, little is known about how these gardens can possibly contribute to conservation purposes in urban areas. Bearing in mind that anthropogenic activities are possible drivers of urban biodiversity, it is vital to quantify socio-economic aspects within urban ecological research. In developing countries, such as South Africa, the inclusion of socio-economic aspects are especially important because there is a wider gap between poor and wealthy households. There are also a larger number of people that are dependent on their gardens for subsistence purposes, such as vegetable gardening. In the Municipal Area of Tlokwe, South Africa, there exists a definite socio-economic gradient from the poorer western to the more affluent eastern part of the city. Five socio-economic status (SES) classes, primarily based on % unemployment, were used in this study. The ultimate aim of this study was therefore to determine the plant- and arthropod diversity within urban domestic gardens along a socio-economic gradient. Vegetable gardens within domestic gardens were selected to quantify plant- and arthropod biodiversity. Biodiversity of adjacent lawns were also sampled for comparative purposes. The study also attempted to determine to what extent socio-economic aspects of city residents may be possible drivers of biodiversity within the gardens. Various other factors that might have an effect on the plant and/or arthropod diversity were included such as soil characteristics, specific management factors of the gardens and other land-uses surrounding domestic gardens. Arthropod diversity was surveyd by means of pitfall traps and suction sampling in eight 0.25 m2 squares along an 8 m transect in each representative garden. Arthropods were identified up to morphospecies level. Vegetation was surveyed along the same transect and total species composition was determined. Plants were identified up to species level. The plant and arthropod surveys were conducted in both the vegetable gardens and lawns of all SES classes. For the soil samples a 1:2.5 water analysis was conducted. A social survey was conducted in all representative gardens by means of a questionnaire and a SPOT 5 satellite imagery was used to determine the land-use types in the areas surrounding the participating gardens. All the above mentioned factors were compared between the different SES classes. Diversity indices for the arthropods, multivariate statistical analyses and ANOVA analyses were applied to test for meaningful variables between socio-economic status classes as well as vegetable gardens and lawns. From the results it was evident that the more affluent SES classes had significantly higher arthropod diversity values, whilst the lower income classes had higher plant diversity. The factor analysis between the plants and arthropods with the surrounding land-uses revealed two significant factors. Firstly, arthropod diversity was influenced by domestic gardens in the surrounding landscape and there was a positive correlation between these two variables. This indicates that a high percentage of surrounding domestic gardens were possible drivers of arthropod diversity. No correlations were evident between plant and arthropod diversity. Secondly, the other significant factor showed that one SES class had a significantly higher percentage of woodlands and grasslands as opposed to two of the other classes that had a significantly higher percentage of built structures within the surrounding area. Differences were also apparent between the SES classes concerning management regimes, financial stability and level of education. The two more affluent SES classes had obtained a higher level of education and income and had management practices that were uncommon in the three poorer SES classes. This study proposes that domestic gardens are a means to conserve biodiversity in cities. Vegetable gardens in domestic gardens will also be able to harbour a larger diversity of plants and arthropods than the lawns. The socio-economic status of residents also had a significant effect on biodiversity and therefore it should be included in studies on urban domestic gardens. This study also provides additional knowledge to the fundamentals of the field of urban ecology and the importance of using domestic gardens as an urban green space for conservation purposes. / Thesis (Master of Environmental Sciences)--North-West University, Potchefstroom Campus, 2013
115

Urban Apiculture – A Way to Reconnect Society and Nature?

Claussnitzer, Marco January 2014 (has links)
In recent years honeybees have attracted a great deal of attention, an attention that seems to be rather unlikely when one looks at the general relationship between humans and the environment, which is often taken for granted. This study aims to look into one kind of corporate initiative in urban apiculture to reconnect humans and nature again. In particular the focus is on motivation, implementation and the impact these initiatives have on sustainable development. A transdisciplinary approach has been adopted that combines different perspectives of beekeepers in the field, scholars and business. It is thereby important to note that adopting apiculture as part of a corporate sustainability strategy is a rather recent trend, which reflects both the scope and the results of the study. This study has found the primary motivation behind apiculture projects for corporations to be raising awareness about the fate of honeybees (Apis mellifera) and supporting honeybee population numbers. This also reflects in the impact on sustainable development. Not only does the urban environment offer an ideal habitat that shows benefits for honeybee health and their honey, but honeybees also benefit the urban environment through their pollination services. And although the connection between corporations and apiculture seems to be alien at first glance, benefits also extend to the corporations themselves, including a greater identification with the corporation by its employees, more cooperation both within one corporation and with other corporations and more publicity. Urban apiculture can thus help reconnecting society and nature in different ways. However, the greater the abundance of honeybees the more limited seem their benefits and initially positive impacts might even turn negative. To prevent this, the study therefore concludes that it is important to decide about the extent in which urban apiculture is adopted on a case by case basis that is possibly supplemented by planting additional forage.
116

Adaptation of trees to the urban environment : Acacia karroo in Potchefstroom, South Africa / by Alida Yonanda Pelser

Pelser, Alida Yonanda January 2006 (has links)
Urban open spaces are of strategic importance to the quality of life of our increasingly urbanized society. Trees and related vegetation are planted and managed within the communities and cities to create or add value to the busy lives of the city dwellers. Trees in towns and cities form an important part of complex urban ecosystems and provide significant ecosystem services and benefits for urban dwellers, for example: reducing particulate pollution, carbon sequestration, decreasing air temperature, decreasing water runoff, aesthetic value and an increase in human health. Trees are solarpowered technology that can help restore balance to dysfunctional urban ecosystems. Trees form strands in the urban fabric that connect people to nature and to each other. The urban environment puts tremendous strain on trees by trenching, limited space for root growth and emission of pollutants into the atmosphere, water and soil. The problem is that the real impact of the urban environment on the trees within our community is unknown. The aim of this investigation was to assess the overall anthropogenic and environmental impacts on urban trees by measuring the tree vitality of Acacia karroo using chlorophyll fluorescence kinetics (JIP-test) and the leaf water potential using a pressure chamber. Tree vitality was quantified as the chlorophyll fluorescence-based performance index (PIABS)T. ree vitality measurements were also correlated with soil physical and chemical data. In the comparative study, an urbanization gradient approach was followed in which results of trees in rural areas were regarded as controls. The gradient approach is used worldwide and provides a background for questions of ecological structure and function. The urbanization gradient was quantified using the V-I-S model, based on % cover of vegetation, impervious surface and soil. Additionally, a model to determine the monetary value of trees in urban environments (SATAM) was tested. All this information could eventually contribute to develop an urban tree management program for Potchefstroom. It was evident from the current study that urbanization has a negative impact on tree vitality. The leaf water potential of a tree was, however, not necessarily negatively impacted upon. Although trees in urban environments did not always have a high vitality (PIABS)t, hey still played a major role in the urban environment. According to the tree appraisal method (SATAM), some of these trees have a value of R60 000. / Thesis (M. Environmental Science (Ecological Remediation and Sustainable Utilisation))--North-West University, Potchefstroom Campus, 2007.
117

Comparison of the urban domestic garden flora along a socio-economic gradient in the Tlokwe City Municipality / Catherina Susanna Lubbe

Lubbe, Catherina Susanna January 2011 (has links)
Urbanisation has increased tremendously over the last 60 years so that more than 50 per cent of the world population now live in cities. This is especially true for in developed countries, but it is expected that developing countries will take the lead in future urban population growth. This increasing trend of urbanisation has severe consequences for the environment, as it fragments and changes natural areas and alter environmental conditions. This has compelled scientists from many different disciplines to focus on the inclusion of humans into ecology as a driving force of change to create a better understanding of urban ecosystems. The diversity of fauna and flora in the urban environment provides a myriad of ecosystem goods (such as food and fuel) and services (e.g. cleaning the air and reducing noise levels). Apart from these tangible benefits, urban green space also provides recreational, educational and social benefits to urban inhabitants. A surprisingly substantial proportion (21‒36 %) of the total urban green space that produces these ecosystem goods and services is located in private yards. This portrays the importance of the flora of this land-use type, but very little is known about garden flora and its potential for conservation. The determinants of diversity and species richness in gardens were found to be different than for semi-natural ecosystems, because of the high anthropogenic influence. One of these is the socio-economic status of the inhabitants. People with higher socio-economic status were found to harbour more diverse species assemblages in their gardens than those of lower socio-economic status. This phenomenon was termed the “luxury concept”. In the Tlokwe City Municipality (TCM), the legacy effects of apartheid created a steep socio-economic gradient as a result of the inequitable distribution of economic, natural and social resources. The aims of this study were to gain information on the flora that is present in the domestic gardens of the TCM and to determine if socio-economic status (SES), a management index (MI) and demographic factors influences the distribution of plant species between these gardens. A total of 835 plant species were recorded from 100 domestic gardens and the majority were of alien origin. This large number of species included some Red Data species, invasive alien species and also many utilitarian species. This portrays gardens as important ex situ conservation habitats, but simultaneously it could also threaten the integrity of our natural ecosystems through the distribution of alien invasive species. The gamma, alpha and beta diversity were determined across five SES classes to describe the patterns of domestic garden plant species diversity in the TCM. In accordance with other studies, correlations showed that the SES of the inhabitants affected the plant species distribution in the study area. This was especially true for the distribution of alien species that are cultivated for their ornamental value. More species were found in areas of high SES than those of lower SES. The other aspect that influenced the distribution of plant species in these gardens were the MI, although this was to a lesser extent than the effect of SES. The confirmation of differences along the SES gradient could be utilised by urban planners and policy makers to correct this imbalance through the provision of urban green spaces where it is needed most. / Thesis (M. Environmental Sciences and Management)--North-West University, Potchefstroom Campus, 2011.
118

Comparison of the urban domestic garden flora along a socio-economic gradient in the Tlokwe City Municipality / Catherina Susanna Lubbe

Lubbe, Catherina Susanna January 2011 (has links)
Urbanisation has increased tremendously over the last 60 years so that more than 50 per cent of the world population now live in cities. This is especially true for in developed countries, but it is expected that developing countries will take the lead in future urban population growth. This increasing trend of urbanisation has severe consequences for the environment, as it fragments and changes natural areas and alter environmental conditions. This has compelled scientists from many different disciplines to focus on the inclusion of humans into ecology as a driving force of change to create a better understanding of urban ecosystems. The diversity of fauna and flora in the urban environment provides a myriad of ecosystem goods (such as food and fuel) and services (e.g. cleaning the air and reducing noise levels). Apart from these tangible benefits, urban green space also provides recreational, educational and social benefits to urban inhabitants. A surprisingly substantial proportion (21‒36 %) of the total urban green space that produces these ecosystem goods and services is located in private yards. This portrays the importance of the flora of this land-use type, but very little is known about garden flora and its potential for conservation. The determinants of diversity and species richness in gardens were found to be different than for semi-natural ecosystems, because of the high anthropogenic influence. One of these is the socio-economic status of the inhabitants. People with higher socio-economic status were found to harbour more diverse species assemblages in their gardens than those of lower socio-economic status. This phenomenon was termed the “luxury concept”. In the Tlokwe City Municipality (TCM), the legacy effects of apartheid created a steep socio-economic gradient as a result of the inequitable distribution of economic, natural and social resources. The aims of this study were to gain information on the flora that is present in the domestic gardens of the TCM and to determine if socio-economic status (SES), a management index (MI) and demographic factors influences the distribution of plant species between these gardens. A total of 835 plant species were recorded from 100 domestic gardens and the majority were of alien origin. This large number of species included some Red Data species, invasive alien species and also many utilitarian species. This portrays gardens as important ex situ conservation habitats, but simultaneously it could also threaten the integrity of our natural ecosystems through the distribution of alien invasive species. The gamma, alpha and beta diversity were determined across five SES classes to describe the patterns of domestic garden plant species diversity in the TCM. In accordance with other studies, correlations showed that the SES of the inhabitants affected the plant species distribution in the study area. This was especially true for the distribution of alien species that are cultivated for their ornamental value. More species were found in areas of high SES than those of lower SES. The other aspect that influenced the distribution of plant species in these gardens were the MI, although this was to a lesser extent than the effect of SES. The confirmation of differences along the SES gradient could be utilised by urban planners and policy makers to correct this imbalance through the provision of urban green spaces where it is needed most. / Thesis (M. Environmental Sciences and Management)--North-West University, Potchefstroom Campus, 2011.
119

Stress physiology and anti-predator behaviour in urban Northwestern Gartersnakes (Thamnophis ordinoides)

Bell, Katherine 02 January 2014 (has links)
Over 50% of the world’s human population resides in urban centres, and this is expected to increase as the global human population grows and people migrate from non-urban to urban centres. Concentrated in these urban areas are anthropogenic disturbances that impose additional challenges on wildlife compared to their non-urban counterparts. These challenges can be stress provoking. Through the release of corticosterone (CORT) reptiles can adapt to these stressors, physiologically and behaviourally, both in the short- and long-term. To investigate the relationships between stress activation and defensive tactics in wild urban Northwestern Gartersnakes (Thamnophis ordinoides) I conducted visual encounter surveys, along edge-focused transects, following a semi-constrained random sampling method. I sampled snakes at five sites, each with a different level of anthropogenic disturbance, in the Greater Victoria Area, BC. I sampled blood, observed anti-predator behaviour, and collected data on characteristics of snakes. The most disturbed site (with the most people, pets, and natural predators) also had the most snakes: those snakes also had highest H:L values (a proxy of CORT) in their blood compared to the other populations. Nevertheless, none of the snakes had H:L values that indicated chronic stress. Stress physiology was not correlated with anti-predator behaviour. More important to anti-predator behaviour was the size, sex/reproductive condition, and cloacal temperature of snakes. Although anthropogenic development can reduce habitat quality for some reptiles, Northwestern Gartersnakes coexist with recreationists at many sites in the District of Saanich. A multi-disciplinary approach is of paramount importance to understand the full effect of anthropogenic influences on wildlife. / Graduate / 0433 / 0329
120

Modified comparative life cycle assessment of end-of-life options for post-consumer products in urban regions

Guidry, Caroline 09 July 2008 (has links)
The environmental impact of consumer goods is becoming a growing concern in the modern world. With the increasing awareness of our daily impact and our effects on such crises as global warming, there has been a recent push to develop better environmental strategies and new industries focused on sustainability and the recycling of a variety of post-consumer goods. In other words, there is a shift towards turning waste into money in the name of the environment. Urban regions provide the perfect setting for such development. The concentration of post-consumer waste makes the mining of recyclable materials economical and the availability of labor needed to support the emerging sustainable industries sets the stage for social, economic and environmental benefits. There are currently several end-of-life (EOL) options for post-consumer products. EOL scenarios include secondary material reclamation, material reclamation, repurpose material reclamation, and waste disposal. Within each of these EOL scenarios exists a myriad of process permutations ranging from various collection schemes and modes of transportation to material processing standards and new recycled product industries. Due to the variety of EOL options for post-consumer products, there is no straight-forward answer to the question Which EOL option is preferred? Thus, under the guidelines of Life Cycle Assessment (LCA) as standardized by the International Standards Organization (ISO) in ISO14040, with the inclusion of social and economic requirements as well, the various EOL scenarios are compared in several impact categories including energy use, greenhouse emissions, waste generation, social implications and economic viability. The results of this comparative analysis provide insight into the potential of a more sustainable urban environment, which is part of a much larger goal of reducing our daily impact on the world around us. One industry sector that contributes to a rather large amount of post-consumer trash each year, nearly 4.7 billion tons, is the carpet industry. Carpet thus occupies a great percentage of overall dedicated waste space according to product density. Within an urban environment, the burden of such a bulky waste product is more evident; thus carpet is used here as a case study for the social, economic and environmental impacts of material mining in urban regions for the improvement of overall industrial sustainability. A comparative EOL study is conducted comparing the social, economic and environmental effects of secondary material reclamation, material reclamation, repurpose material reclamation, and waste disposal of post-consumer carpet (PCC) within the thirteen county urban region of Atlanta, GA.

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